How to use it

Choose or drop a PDF file.
Type the watermark text, or switch to Image or logo and choose a PNG or JPEG.
Set size, colour, opacity, rotation and position, or tile it across the page. Watch the preview of page 1.
Optionally limit it to certain pages, then select Add watermark and download the PDF.

How it works

The watermark is drawn over each selected page with pdf-lib. Text uses the standard PDF font Helvetica Bold, so it stays sharp at any zoom and is stored as text. Text with characters Helvetica cannot show (for example Cyrillic, Greek, Arabic, Chinese or Turkish ı and ş) is rendered with your system font and added as a high-resolution image instead.

Image watermarks are embedded once and reused on every page, so they add little to the file size. Their width is a share of each page's width, so the logo scales with the page. Opacity applies to the whole watermark, letting the content underneath show through.

Positions refer to the page as it is displayed, also on pages stored with a rotation. Tiled places the watermark in a staggered grid that covers the whole page.

A watermark marks a document; it does not protect it. It is part of the page content, but anyone with a PDF editor can remove or cover it, and the original text remains selectable. Encrypted or password-protected PDFs cannot be watermarked.

Examples

Draft contract

The text DRAFT at 96 pt, red, 25% opacity, rotated 45° in the centre makes the status clear without hiding the text.

Company logo on a brochure

A transparent PNG logo at 15% of the page width in the bottom right of every page, at 60% opacity.

Sample copy

SAMPLE tiled across pages 1-3 at 20% opacity discourages reuse of a preview you send to a client.

Frequently asked questions

Can the watermark be removed?

Yes, with enough effort. It is drawn on top of the page, so PDF editors can delete it. For stronger protection, convert the watermarked PDF to images (for example with Compress PDF in Strong mode), which merges watermark and content.

Why does my text appear as an image?

The built-in PDF font only covers Western European characters. Other characters are rendered with your system font as an image so they appear correctly.

Can I use an SVG logo?

Not directly. Convert it to PNG first, for example with the SVG to PNG tool, and use the PNG.

Privacy

The PDF and the watermark image are processed in your browser. They are not uploaded, stored or included in analytics; only an anonymous event that the tool was used is counted.